Here are the gang as the (Pokemonized) Four Guardians of Asian mythology:

Brock as Genbu the Black Torterra:

$BrockGenbu.png

Misty as Seiryu the Blue Dragon:

$MistySeiryu.png

Serena as Byakko the White Raikou (with ears):

$SerenaByakko.png

Ash as Suzaku the Red Phoenix:

$AshSuzaku.png